Method for oxidative cleavage of compounds with unsaturated double bond

ABSTRACT

A method for oxidative cleavage of a compound with an unsaturated double bond is provided. The method includes the steps of:(A) providing a compound (I) with an unsaturated double bond, a trifluoromethyl-containing reagent, and a catalyst;wherein, the catalyst is represented by Formula (II):M(O)mL1yL2z  (II);wherein, M, L1, L2, m, y, z, R1, R2 and R3 are defined in the specification; and(B) mixing the compound with an unsaturated double bond and the trifluoromethyl-containing reagent to perform an oxidative cleavage of the compound with the unsaturated double bond by using the catalyst in air or under oxygen atmosphere condition to obtain a compound represented by Formula (III):

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefits of the Taiwan Patent Application Serial Number 109100028, filed on Jan. 2, 2020, the subject matter of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to a method of oxidative cleavage and, more particularly, to a method of oxidative cleavage for a compound with an unsaturated double bond under an aerobic condition to obtain a carbonyl compound.

2. Description of Related Art

Oxidative cleavage is one of the important reactions for a compound with an unsaturated double bond, such as olefins. Generally, olefins can be subjected to an oxidative cleavage reaction by (1) ozone; (2) high oxidation state metal oxides, such as potassium permanganate (KMnO₄), or osmium tetroxide (OsO₄); and (3) Pd/Cu catalysis.

However, due to the use of strong oxidants and peroxides for the reaction, the oxidative cleavage of olefins has the disadvantages of high cost and strict operating conditions, and it has difficulty in mass production. In addition, half of the oxidation products in the oxidative cleavage reaction is not the expected product in almost all cases, and it causes additional waste and environmental pollution.

Therefore, there is a strong and urgent demand to develop a method of oxidative cleavage for a compound with an unsaturated double bond to overcome the disadvantages of common oxidative cleavage and increase economic benefits.

SUMMARY OF THE INVENTION

In view of this, the present disclosure provides a method for oxidative cleavage of a compound with an unsaturated double bond. The method can be performed by using air or oxygen as an oxidant source under mild conditions, thereby overcoming the drawbacks of high cost or strict operating conditions with respect to conventional oxidative cleavage reactions. At the same time, the other half of the oxidation products are introduced with trifluoromethyl group, which greatly improves economic value.

The present disclosure provides a method for oxidative cleavage of a compound with an unsaturated double bond, comprising the steps of: (A) providing a compound (I) with an unsaturated double bond, a trifluoromethyl-containing reagent, and a catalyst;

wherein, R₁ and R₂ are each independently H, C₁₋₂₀ alkyl, C₃₋₂₀ cycloalkyl, C₆₋₁₈ aryl, or C₄₋₁₈ heteroaryl, or R₁ and R₂ are fused to be C₆₋₁₈ aralkyl; R₃ is H, C₁₋₁₀ alkyl, C₃₋₁₀ cycloalkyl, C₆₋₁₀ aryl, or C₄₋₁₀ heteroaryl, with the proviso that R₁, R₂ and R₃ are not H at the same time; wherein the catalyst is represented by Formula (II): M(O)_(m)L¹ _(y)L² _(z)  (II) wherein, M is a metal selected from the group consisting of IVB, VB, VIB, and actinides; L¹ and L² are each a ligand; m and y are integers greater than or equal to 1; and z is an integer greater than or equal to 0;

(B) mixing the compound with an unsaturated double bond and the trifluoromethyl-containing reagent to perform an oxidative cleavage of the compound with the unsaturated double bond by using the catalyst in air or under oxygen atmosphere condition to obtain a compound represented by Formula (III):

The compound (1) with an unsaturated double bond according to the present disclosure may be an olefin compound. In the compound (I) with an unsaturated double bond, R₁ and R₂ are each independently H, C₁₋₂₀ alkyl, C₃₋₂₀ cycloalkyl, C₆₋₁₈ aryl, or C₄₋₁₈ heteroaryl, or R₁ and R₂ are fused to be C₆₋₁₈ aralkyl; R₃ is H, C₁₋₁₀ alkyl, C₃₋₁₀ cycloalkyl, C₆₋₁₀ aryl, or C₄₋₁₀ heteroaryl. Preferably, R₁ and R₂ are each independently H, C₁₋₁₀ alkyl, C₃₋₁₀ cycloalkyl, C₆₋₁₄ aryl, or C₄₋₁₂ heteroaryl, or R₁ and R₂ are fused to be C₆₋₁₂ aralkyl; R₃ is H, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, or C₄₋₁₀ heteroaryl. More preferably, R₁ and R₂ are each independently H, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₄ aryl, or C₄₋₁₀ heteroaryl, or R₁ and R₂ are fused to be C₆₋₁₀ aralkyl; R₃ is H, C₁₋₆ alkyl, or C₃₋₆cycloalkyl.

In addition, in the compound (I) with an unsaturated double bond, R, R₂ and R₃ are not H at the same time

In the present disclosure, the catalyst may be represented by Formula (II). In the catalyst represented by Formula (II), L¹ is a ligand and preferably selected from the group consisting of OTf, OTs, NTf₂, halogen, RC(O)CH₂C(O)R, OAc, OC(O)R, OC(O)CF₃, OMe, OEt, O-iPr, and butyl, wherein R is alkyl (preferably C₁₋₆ alkyl, more preferably C₁₋₃ alkyl). Furthermore, L² is a ligand and preferably selected from the group consisting of Cl, H₂O, CH₃OH, EtOH, THF, CH₃CN,

and ligand containing C═N unit.

In the present disclosure, the “ligand containing C═N unit” may comprise pyridine, oxazole, oxazoline, or imidazole. However, the present disclosure is not limited thereto. Specific example comprises 2,2′-bipyridyl, 3-chloropyridine, 2,6-dichloropyridine, 3,5-dichloropyridine, 2,6-di-tert-butylpyridine, 1-methylimidazole, 1,2-dimethylimidazole. However, the present disclosure is not limited thereto.

In one embodiment of the present disclosure, the “ligand containing C═N unit” may be represented by Formula (IV):

wherein, R₄ and R₅ are each independently halogen, nitro, C₁₋₁₀ alkyl, C₆₋₁₈ aryl, or C₄₋₁₈ heteroaryl. Preferably, R₄ and R₅ may be each independently Cl, Br, NO₂ or C₁₋₁₀ alkyl.

In another embodiment, the “ligand containing C═N unit” may be represented by Formula (V):

wherein R₆ and R₇ are each independently H, C₁₋₅ alkyl or C₃₋₄ cycloalkyl.

Further, in the catalyst represented by Formula (II), M may be a metal selected from the group consisting of IVB, VB, VIB, and actinides. In one aspect, M is a group IVB transition element, m is 1 and y is 2; wherein M may be Ti, Zr, or Hf. In another aspect, M is a group VB transition element, m is 1 and y is 2 or 3; wherein M may be V or Nb. In another aspect, M is a group VIB transition element, m is 1 and y is 4; wherein M may be Mo, W, or Cr. In another aspect, M is a group VIB transition element, m is 2 and y is 2; wherein M is Mo, W, or Cr. In yet another aspect, M is selected from the actinides, m is 2 and y is 2; wherein M is U.

In addition, in the catalyst of Formula (II), z may be an integer greater than or equal to 0. When z is 0, the specific example of the catalyst of Formula (II) may be MoO₂Cl₂, V(O)Cl₃, V(O)O-iPr)₃, V(O)Cl₂, V(O)(OAc)₂, V(O)(O₂CCF₃)₂, Ti(O)(acac)₂, Zr(O)Cl₂, Hf(O)Cl₂, Nb(O)Cl₂, MoO₂(acac)₂, V(O)(OTs)₂, VO(OTf)₂, or V(O)(NTf₂)₂. However, the present disclosure is not limited thereto. When z is an integer greater than 0, the specific example of the catalyst of Formula (II) may be any of formulas (II-1) to (II-4):

However, the present disclosure is not limited thereto.

The trifluoromethyl-containing reagent according to the present disclosure may be a monotrifluoromethyl- or perfluoroalkyl-containing reagent. The specific example comprises 3,3-Dimethyl-1-(trifluoromethyl)-1,2-benziodoxole, 3,3-Dimethyl-1-(perfluroalkyl)-1,2-benziodoxole, 3-oxo-1-(trifluoromethyl)-1,2-benziodoxole, 3-oxo-1-(perfluroalkyl)-1,2-benziodoxole, trifluomethyl dibenzothiophenium salts, perfluoroalkyl dibenzothiophenium salt, CF₃SO₂Na, and CF₃(CF₂), SO₂Na (n=1-6). However, the present disclosure is not limited thereto.

In the compound represented by Formula (III), R₁ and R₂ are each independently H, C₁₋₂₀ alkyl, C₃₋₂₀ cycloalkyl, C₆₋₁₈ aryl, or C₄₋₁₈ heteroaryl, or R₁ and R₂ fused to be C₆₋₁₈ aralkyl group. Preferably, R₁ and R₂ are each independently H, C₁₋₁₀ alkyl, C₃₋₁₀ cycloalkyl, C₆₋₁₄ aryl, or C₄₋₁₂ heteroaryl, or R₁ and R₂ fuse to be C₆₋₁₂ aralkyl group. More preferably, R₁ and R₂ are each independently H, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₂ aryl, or C₄₋₁₀ heteroaryl, or R₁ and R₂ fused to be C₆₋₁₀ aralkyl group. In one embodiment of the present disclosure, R₁ and R₂ are not H at the same time.

In the present disclosure, step (B) may further obtain a trifluoroketone- or trifluoroaldehyde-containing compound, trifluoroalkyl alcohol or a combination thereof.

wherein R₃ is H, C₁₋₁₀ alkyl, C₃₋₁₀ cycloalkyl, C₆₋₁₀ aryl, or C₄₋₁₀ heteroaryl; n is an integer of 0 or 1 to 6.

In one embodiment of the present disclosure, R₃ is preferably H, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, or C₄₋₁₀ heteroaryl; n is an integer of 0 or 1 to 3. More preferably, R₃ is preferably H, C₁₋₆ alkyl, or C₃₋₆ cycloalkyl; n is 0 or 1.

In another aspect of the present disclosure, the step (B) may further comprise adding an additive to the mixture of the compound with an unsaturated double bond and the trifluoromethyl-containing reagent, wherein the additive may be trimethylsilyl cyanide (TMSCN), anhydride or a combination thereof. However, the present disclosure is not limited thereto.

Herein, the term “alkyl” of the present disclosure includes unsubstituted alkyl or alkyl group substituted with halogen, nitro, alkenyl, cycloalkyl, alkoxy, aryl, or heteroaryl. The terms “cycloalkyl”, “aryl”, “heteroaryl” and “aralkyl” include unsubstituted groups or groups substituted with alkyl, halogen, nitro, alkenyl, cycloalkyl, alkoxy, aryl, or heteroaryl.

In summary, the present disclosure introduces a trifluoromethyl-containing reagent into an oxidative cleavage reaction. The reaction can use air or oxygen as an oxidant source under mild conditions, and the reaction is conducted using a proper catalyst to obtain a corresponding ketone or aldehyde. In addition, because of the introduction of the trifluoromethyl reagent, the other half of the oxidative cleavage reaction will be converted into trifluoromethyl or perfluoromethylketone, or trifluoromethyl aldehyde, perfluoroalkyl aldehyde, and trifluoromethyl or perfluroalkyl ethanol, which can be further used.

Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Different embodiments of the present invention are provided in the following description. These embodiments are meant to explain the technical content of the present invention, but not meant to limit the scope of the present invention. A feature described in an embodiment may be applied to other embodiments by suitable modification, substitution, combination, or separation.

Preparation of an Unsaturated Double Bond with an Unsaturated Double Bond

In a flame-dried, 50-mL, two-necked, round-bottomed flask was placed methyltriphenylphosphonium bromide (3.0 equiv) dissolved in 1 mL THF (0.2 M) at 0° C. Then added tert-BuOK (3.0 equiv) stirred at 0° C. After 30 minutes, add ketone or aldehyde (1.0 equiv) and let it warm to room temperature. After having been complete of the reaction, the reaction was quenched with H₂O and extracted with EtOAc for three times. The combined organic layers dried over MgSO₄, and the filtrate was concentrated. The crude product was purified using flash column chromatography on silica gel with pure hexane as eluent to afford styrene derivatives.

1-nitro-4-(prop-1-en-2-yl)benzene

¹H NMR (CDCl₃, 400 MHz) δ 8.19 (d, J=9.0 Hz, 2H), 7.60 (d, J=9.1 Hz, 2H), 5.52 (t, J=0.8 Hz, 1H), 5.29 (t, J=1.3 Hz, 1H), 2.19 (dd, J=1.5, 0.8 Hz, 3H); ¹³C NMR (CDCl₃, 100 MHz) δ 147.6, 147.0, 141.6, 126.2, 123.6, 116.4, 21.6; TLC R_(f) 0.47 (hexane); HRMS (FI) Calcd for C₉H₉NO₂: 163.0628, found: 163.0628.

4-(prop-1-en-2-yl)phenyl acetate

¹H NMR (CDCl₃, 500 MHz) δ 7.47 (d, J=9.0 Hz, 2H), 7.05 (d, J=8.5 Hz, 2H), 5.34 (s, 1H), 5.08 (s, 1H), 2.30 (s, 3H), 2.14 (s, 3H); ¹³C NMR (CDCl₃, 100 MHz) δ169.5, 150.0, 142.4, 140.0, 126.5, 121.2, 112.6, 21.8, 21.1; TLC R_(f) 0.38 (hexane); HRMS (FI) Calcd for C₁₁H₁₂O₂: 176.0832, found: 176.0828.

1-methoxy-4-(prop-1-en-2-yl)benzene

¹H NMR (CDCl₃, 400 MHz) δ7.43 (d, J=8.9 Hz, 2H), 6.87 (d, J=8.9 Hz, 2H), 5.29 (dq, J=1.6, 0.7 Hz, 1H), 4.99 (quin, J=1.5 Hz, 1H), 2.13 (t, J=0.9 Hz, 3H), 3.82 (s, 3H); ¹³C NMR (CDCl₃, 100 MHz) δ 159.0, 142.5, 133.7, 126.6, 113.5, 110.6, 55.3, 21.9; TLC R_(f) 0.42 (hexane); HRMS (FI) Calcd for C₁₀H₁₂O: 148.0883, found: 148.0887.

2-(prop-1-en-2-yl)naphthalene

¹H NMR (400 MHz, CDCl₃) δ 7.87-7.82 (m, 4H), 7.71-7.68 (m, 1H), 7.51-7.44 (m, 2H), 5.56 (s, 1H), 5.22-5.21 (m, 1H), 2.29 (s, 3H); ¹³C NMR (100 MHz, CDCl₃) δ143.0, 138.3, 133.3, 132.8, 128.2, 127.7, 127.5, 126.1, 125.8, 124.2, 123.9, 113.0, 21.8; TLC R_(f) 0.49 (hexane); HRMS (FI) Calcd for C₃H₁₀: 168.0934, found: 168.0928.

4-(prop-1-en-2-yl)pyridine

¹H NMR (CDCl₃, 400 MHz) δ 8.55 (d, J=6 Hz, 2H), 7.33 (d, J=5.2 Hz, 2H), 5.57 (d, J=0.6 Hz, 1H), 5.26 (d, J 1.0 Hz, 2H), 2.14 (s, 3H); ¹³C NMR (CDCl₃, 100 MHz) δ 150.7, 149.4, 148.2, 140.7, 121.0, 119.9, 115.8, 20.6; TLC R_(f) 0.30 (EtOAc/Hexane=1/5); HRMS (FI) Calcd for C₈H₉N: 119.0730, found: 119.0730.

2-(prop-1-en-2-yl)pyridine

¹H NMR (CDCl₃, 400 MHz) 8.68 (td, J=4, 0.8 Hz, 1H), 8.03 (dd, J=8.0, 0.8 Hz, 1H), 7.82 (dt, J=7.8, 1.6 Hz, 1H), 7.44-7.48 (m, 1H), 2.72 (s, 3H); ¹³C NMR (CDCl₃, 100 MHz) δ 199.4, 153.1, 148.6, 136.4, 136.1, 126.7, 121.1, 25.3; TLC R_(f)0.25 (EtOAc/Hexane=1/5); HRMS (FI) Calcd for C₈H₉N: 119.0730, found: 119.0729.

2-(prop-1-en-2-yl)thiophene

¹H NMR (400 MHz, CDCl₃) δ7.15 (dd, J=5.1, 1.1 Hz, 1H), 7.02 (dd, J=3.6, 1.1 Hz, 1H), 6.96 (dd, J=5.1, 3.6 Hz, 1H), 5.37 (s, 1H), 4.94 (m, 1H), 2.14 (m, 3H); ¹³C NMR (125 MHz, CDCl₃) δ145.8, 137.1, 127.2, 124.2, 123.5, 111.1, 21.8; TLC R_(f) 0.43 (hexane); HRMS (FI) Calcd for C₇H₈S: 124.0341, found: 124.0340.

Prop-1-en-2-ylcyclohexane

¹H NMR (CDCl₃, 400 MHz) δ 4.66 (s, 2H), 1.90-1.82 (m, 2H), 1.78-1.1.71 (m, 7H), 1.30-1.11 (m, 6H); ¹³C NMR (CDCl₃, 100 MHz) δ 151.3, 107.8, 45.5, 32.0, 26.8, 26.4, 20.9; TLC R_(f)0.6 (hexane); HRMS (FI) Calcd for C₉H₁₆: 124.1247, found: 124.1243.

3-bromoprop-1-en-2-yl)benzene

¹H NMR (CDCl₃, 400 MHz) δ 7.51-7.34 (m, 5H), 5.57 (s, 1H), 5.50 (s, 1H), 4.40 (s, 2H); ¹³C NMR (CDCl₃, 100 MHz) δ 144.2, 137.6, 128.5, 128.3, 126.1, 117.2, 34.2; TLC R_(f) 0.51 (hexane); HRMS (EI) Calcd for C₉H₉Br: 195.9882, found: 195.9882.

(1-cyclopropylvinyl)benzene

¹H NMR (CDCl₃, 400 MHz) δ 7.62-7.59 (m, 2H), 7.37-7.26 (m, 3H), 5.28 (s, 1H), 4.94 (s, 1H), 1.68-1.64 (m, 1H), 0.87-0.82 (m, 2H), 0.61-0.58 (m, 2H); ¹³C NMR (CDCl₃, 100 MHz) δ149.4, 141.6, 128.1, 127.4, 126.1, 109.0, 15.6, 6.7; TLC R_(f) 0.48 (hexane); HRMS (F) Calcd for C₁₁H₁₂: 144.0934, found: 144.0936.

(1-cyclohexylvinyl)benzene

¹H NMR (CDCl₃, 400 MHz) δ 7.36-7.25 (m, 5H), 5.14 (s, 1H), 5.01 (s, 1H), 2.43 (t, J=11.6 Hz, 1H), 1.86-1.70 (m, 5H), 1.38-1.13 (m, 5H); ¹³C NMR (CDCl₃, 100 MHz) δ 154.99, 142.97, 128.10, 126.97, 126.62, 110.31, 42.58, 32.71, 26.84, 26.45; TLC R_(f) 0.5 (hexane); HRMS (FI) Calcd for C₁₄H₁₈: 186.1403, found: 186.1402.

(3,3-dimethylbut-1-en-2-yl)benzene

¹H NMR (CDCl₃, 400 MHz) δ 7.31-7.26 (m, 3H), 7.16-7.14 (m, 2H), 5.18 (d, J=2.0 Hz, 1H), 4.77 (d, J=1.6 Hz, 1H), 1.13 (s, 9H); ¹³C NMR (CDCl₃, 100 MHz) δ 159.8, 143.5, 129.0, 127.2, 126.2, 111.5, 36.1, 29.6; TLC R_(f) 0.4 (hexane); HRMS (FI) Calcd for C₁₂H₁₆: 160.1247, found: 160.1247.

1-methylene-2,3-dihydro-1H-indene

¹H NMR (CDCl₃, 400 MHz) δ7.52-7.50 (m, 1H), 7.28-7.20 (m, 3H), 5.46 (t, J=2.4 Hz, 1H), 5.04 (t, J=2.4 Hz, 1H), 3.01-2.98 (m, 2H), 2.83-2.78 (m, 2H); ¹³C NMR (CDCl₃, 125 MHz) δ150.6, 146.7, 141.1, 128.2, 126.4, 125.3, 120.6, 102.4, 31.2, 30.1; TLC R_(f) 0.5 (hexane); HRMS (FI) Calcd for C₁₀H₁₀: 130.0777, found: 130.0776.

Synthesis of Catalyst (II)-1

In the present embodiment, the catalyst can be synthesized according to the following chemical equation. V(O)SO_(4(aq))+BaX_(2(aq))→V(O)X_(2(aq))+BaSO_(4(s)) V(O)SO_(4(aq))+Ba(OC(O)R)_(2(aq))→V(O)(OC(O)R)_(2(aq))+BaSO_(4(s)) V(O)SO_(4(aq))+Ba(OTf)_(2(aq))→V(O)(OTf)_(2(aq))+BaSO_(4(s)) V(O)SO_(4(aq))+Ba(OTs)_(2(aq))→V(O)(OTs)_(2(aq))+BaSO_(4(s)) V(O)SO_(4(aq))+Ba[(O₃SC₆H₄CHCH₂)_(n)]_(2(aq))→V(O)[(O₃SC₆H₄CHCH₂)_(n)]_(2(aq))+BaSO_(4(s))

In a flame-dried, 50-mL, two-necked, round-bottomed flask was placed vanadyl sulfate-VOSO₄-5H₂O (VOSO₄.5H₂O, 2.5 mmol) followed by addition of anhydrous MeOH (2.5 mL). To the above solution, a solution of Ba(OTf)₂ (1 equiv, 2.5 mmol) in MeOH (2.5 mL) was slowly added at ambient temperature. After stirring for 30 minutes, the reaction mixture became turbid with copious amount of barium sulfate precipitation. Centrifugation (6000 rpm) for the mixture was performed for 30 minutes. The decanted solution was evaporated to give a dark green or faint blue solid which was further dried at 120° C. for 4 hours in vacuo. The resultant catalyst can be stored at ambient temperature for several weeks in dry cabinet and can be used directly.

Synthesis of catalyst (II)-2

To the solution of 3,5-di-tert-butyl-2-hydroxybenzaldehyde (1217 mg, 5.0 mmol, 1.0 equiv) in MeOH (12.5 mL) was added L-tert-leucine (721 mg, 5.5 mmol, 1.1 equiv) or other 18 natural L-α-amino acids (721 mg, 5.5 mmol, 1.1 equiv) and NaOAc (902 mg, 11.0 mmol, 2.2 equiv). After stirring at 80° C. for 18 hours, the reaction mixture was gradually cooled to ambient temperature and a solution of VOSO₄.5H₂O (1392 mg, 5.5 mmol, 1.1 equiv) in MeOH (5.0 mL) was added. After the reaction was performed at ambient temperature for 6 hours, the reaction mixture was concentrated under reduced pressure. The resulting dark black solid was washed with water (5×30 mL) and dried in vacuo to afford a pure oxidovanadium(IV) catalyst. The corresponding analytically pure oxidovanadium(V) methoxide (or hydroxide) complex (11-1) was obtained by re-crystallization from oxygen saturated MeOH.

Catalyst (II-1)

Yield: 84%; black solid. ¹H NMR (CD₃OD, 500 MHz) S 8.60 (bs, 1H), 7.68 (d, J=2.2 Hz, 1H), 7.48 (d, J=2.3 Hz, 1H), 4.14 (s, 1H), 1.47 (s, 9H), 1.35 (s, 9H), 1.21 (s, 9H); ⁵¹V NMR (CD₃OD, 132 MHz) δ −565.0; ¹³C NMR (CD₃OD, 126 MHz) δ 180.1, 168.9, 161.7, 143.5, 138.6, 132.4, 129.5, 129.4, 121.9, 84.7, 49.6, 49.3, 49.2, 49.0, 48.8, 48.6, 48.4, 38.3, 36.3, 35.3, 31.8, 30.3, 28.1; IR (KBr) 3370 (br, w), 2959 (w), 2871 (w), 1698 (m), 1668 (m), 1620 (s, C═N), 1580 (w), 1524 (m, COO), 1480 (w), 1456 (w), 1373 (w), 1322 (w), 1285 (w), 1182 (w), 1071 (w), 986 (m, V═O); [α]_(D) ³⁴ +36.53 (c 0.1, CH₂Cl₂); TLC R_(f) 0.37 (CH₃OH/CH₂Cl₂, 1/8); HRMS (ESI) [M+H]⁺ Calcd for C₂₂H₃₄NO₅V: 444.1959, found: 444.1949.

Catalyst (II-2)

Yield: 57%; black solid. ¹H NMR (CD₃OD, 400 MHz) δ 8.54 (bs, 1H), 7.66 (d, J=2.4 Hz, 1H), 7.62 (d, J=2.4 Hz, 1H), 4.15 (s, 1H), 3.33 (s, OCH₃), 1.44 (s, 9H), 1.18 (s, 9H); ⁵¹V NMR (CD₃OD, 105 MHz) δ −567.6; ¹³C NMR (CD₃OD, 126 MHz) δ 167.7, 142.3, 136.9, 136.2, 135.0, 134.6, 123.7, 111.9, 84.7, 49.8, 38.3, 37.2, 36.2, 29.9, 28.0, 27.4; IR (KBr) 2965 (s), 2913 (m), 2869 (m), 1663 (s), 1615 (s, C═N), 1578 (m), 1548 (m, COO), 1480 (w), 1429 (m), 1368 (m), 1320 (m), 1297 (s), 1181 (m), 1055 (w), 1031 (w), 993 (m, V═O); [α]_(D) ³⁴ −126.4 (c 0.1, CH₃OH); TLC R_(f)0.20 (CH₃OH/CH₂Cl₂, 1/9); HRMS (ESI) [M+H]⁺ Calcd for C₁₈H₂₅BrNO₅V: 466.0427; found: 466.0428.

Catalyst (II-3)

Yield: 75%; black solid. ¹H NMR (CD₃OD, 400 MHz) δ 8.56 (bs, 1H), 7.96 (d, J=2.3 Hz, 1H), 7.78 (d, J=2.3 Hz, 1H), 4.18 (s, 1H), 1.20 (s, 9H); ⁵¹V NMR (CD₃OD, 105 MHz) δ −557.0; ¹³C NMR (CD₃OD, 126 MHz) δ 179.1, 167.2, 159.6, 141.7, 136.7, 123.6, 114.8, 110.9, 84.8, 49.9, 38.2, 28.1, 36.2, 29.9, 28.0, 27.4; IR (KBr) 3370 (br, w), 2959 (w), 2871 (w), 1698 (m), 1668 (m), 1620 (s, C═N), 1580 (w), 1524 (m, COO), 1480 (w), 1456 (w), 1373 (w), 1322 (w), 1285 (w), 1182 (w), 1071 (w), 986 (m, V═O); [α]_(D) ³⁴ −40.8 (c 0.1, CH₂Cl₂); TLC R_(f)0.12 (CH₃OH/CH₂Cl₂, 1/10); HRMS (ESI) [M+H]⁺ Calcd for C₁₄H₁₆Br₂NO₅V: 489.8880, found: 489.8888.

Catalyst (II-4)

Yield: 81%; black solid. ¹H NMR (CD₃OD, 400 MHz) δ 8.71 (bs, 1H), 8.54 (d, J=2.6 Hz, 1H), 8.39 (d, J=2.5 Hz, 1H), 4.24 (s, 1H), 3.31 (s, OCH₃), 1.49 (s, 9H), 1.22 (s, 9H); ⁵¹V NMR (CD₃OD, 105 MHz) δ 549.8, −568.8; ¹³C NMR (CD₃OD, 126 MHz) δ 168.0, 140.5, 139.1, 130.1, 130.0, 128.4, 127.6, 121.5, 84.9, 38.3, 36.5, 29.7, 28.0; IR (KBr) 2965 (w), 2916 (w), 2879 (w), 1627 (m, C═N), 1598 (m, COO), 1509 (w), 1326 (m), 1326 (w), 1225 (w), 1187 (w), 1113 (w), 1034 (w), 990 (w), 927 (w, V═O); MS (ESI) 850 (M₂O+H₂O, 90), 419 (MOH+H+, 9), 417 (MOH−1⁺, 100); [α]_(D) ³⁴ 83.93 (c 0.1, CH₃OH); TLC R_(f) 0.30 (CH₃OH/CH₂Cl₂, 1/4); Anal. Calcd. For [(H₂O)MOH]: C, 46.80; H, 5.78; N, 6.42. Found: C, 45.57; H, 5.83; N, 6.15.

Oxidative Cleavage

In a flame-dried, 50-mL, two-necked, round-bottomed flask was placed 5 mol % VO(OTf)₂. 5H₂O (11.8 mg, 0.025 mmol, 0.05 equiv) and 6 mol % additive (21.5 mg, 0.030 mmol, 0.06 equiv) and trifluoromethyl- or perfluoromethyl-containing reagent (346.6 mg, 1.05 mmol, 1.5 equiv) dissolved in 2.5 mL acetone. Then, α-methylstyrene (65 μL, 0.70 mmol, 1.0 equiv) was added. After having the reaction finished, the solvent was removed in vacuo, and the crude product was purified by using flash column chromatography on silica gel (ethyl acetate/hexane=1/8) to afford the product. The result is shown in Table 1.

TABLE 1 Trifluoromethyl- Time Yield Embodiment Catalyst containing reagent Additive (h) (%) A-1 Cu(CH₃CN)₄PF₆

36 28 A-2 VO(OTf)₂•5H₂O

48 56 A-3 VO(OTf)₂•5H₂O CF₃SO₂Na (1.2 eq)

96 80 A-4 II-1

— 48 81 A-5 II-2

— 48 86 A-6 II-3

— 46 97 A-7 II-4

— 46 82

It can be found in Table 1 that the yield is low (28%) when the oxidative cleavage was performed with commercial catalyst Cu(CH₃CN)₄PF₆. The yield can be doubled or tripled when the catalyst V(O)(OTf)₂ was used in the reaction. When the reaction was performed with the catalyst of Formula (II-1) to Formula (II-4), the yield (81-97%) is significantly improved.

In aflame-dried, 25-mL, two-necked, round-bottomed flask was placed 5 mol % catalyst (eq II-3) and trifluoromethyl- or perfluoromethyl-containing reagent (1.5 equiv) dissolved in acetone (I mL). Then, a compound (1-1) (1.0 equiv) with an unsaturated double bond was added. After having the reaction finished, the solvent was removed in vacuo, and the crude product was purified by using flash column chromatography on silica gel (ethyl acetate/hexane=1/8) to afford the product. The result is shown in Table 2.

TABLE 2 Time Yield Embodiment R₁ R₂ (h) (%) B-1 C₆H₅ CH₃ 46 97 B-2 4-MeC₆H₄ CH₃ 46 96 B-3 4-PhC₆H₄ CH₃ 48 90 B-4 4-ClC₆H₄ CH₃ 47 95 B-5 4-BrC₆H₄ CH₃ 47 93 B-6 4-NO₂C₆H₄ CH₃ 144 96 B-7 4-CH₃CO₂C₆H₄ CH₃ 72 92 B-8 4-MeOC₆H₄ CH₃ 84 95 B-9 3-MeC₆H₄ CH₃ 47 91 B-10 2-MeC₆H₄ CH₃ 46 93 B-11 2-Naphthyl CH₃ 46 90 B-12 4-Py CH₃ 120 92 B-13 2-Py CH₃ 144 90 B-14 2-Th CH₃ 45 93 B-15 cyclohexyl CH₃ 50 92

With the catalyst of Formula (II-3) of the present disclosure, the oxidative cleavage is carried out without adding additives. The resultant product with high isolated yield (90-97%) can be obtained in the aromatic system, and the reaction time is 46 to 144 hours. Also, the resultant product with high isolated yield (90-93%) can be obtained in the heteroaryl system, and the reaction time is 45 to 144 hours. The isolated yield is up to 92% in the cycloalkyl system, and the reaction time is 50 hours.

In addition, through ¹⁹F NMR spectroscopic analysis, it is found that the other half of the main oxidative cleavage is converted to trifluoromethylketone or trifluoroaldehyde and trifluoroethanol (or the corresponding trifluoromethyl alcohol) rather than formaldehyde or 1,3,5-trioxane after the oxidative cleavage.

The reaction was performed in the same manner as described above, and the result is shown in Table 3.

TABLE 3 Yield Embodiment R₁ R₂ Time (h) (%) C-1 C₆H₅ CH₂Br 193 91 C-2 C₆H₅ cy-Pr 90 89 C-3 C₆H₅ cy-hex 96 95 C-4 C₆H₅ t-Bu 192 92 C-5 C₆H₅ Ph 48 95 C-6

45 95

It was found that if R₁ of the compound (I) with an unsaturated double bond was designated as phenyl to perform the oxidative cleavage reaction, the isolated yield was 91-92% with a longer reaction time (192-193 hours) when R₂ was an alkyl system. When R₂ was a cycloalkyl system, the yield is 89-95%, and the reaction time was shortened to 90-96 hours. In addition, when R₂ is aryl or R₁ and R₂ are fused to be an aralkyl system, the yield is up to 95%, and the reaction time is significantly reduced to 45-48 hours.

The reaction was performed in the same manner as described above, and the result is shown in Table 4.

TABLE 4 Time Yield Embodiment R₁ R₃ (h) (%) D-1 H CH₃ 96 60  D-2 CH₃ CH₃ 96 82^(a) ^(a)the reaction was performed at 50° C.

The reaction was performed in the same manner as described above, and the result is shown in Table 5.

TABLE 5 Time Yield Embodiment Ar (h) (%) E-1 4-XC₆H₄ ^(b) 17-24 38-40 E-2 4-CH₃CO₂C₆H₄ 26 41 E-3 4-Me or 4-PhC₆H₄ 18-19 41-43 E-4 3-ClC₆H₄ 96 62 E-5 2-XC₆H₄ ^(b) 20-26 58-65 ^(b)X is halogen (F, Cl, Br, I)

When the R₂ and R₃ of the compound (I) with an unsaturated double bond is H, the corresponding benzaldehyde, trifluoroaldehyde and trifluoroethanol can be obtained.

¹H NMR (CDCl₃, 400 MHz) δ 7.97-7.95 (m, 2H), 7.58-7.54 (m, 1H), 7.84-7.44 (m, 2H), 2.6 (s, 3H); ¹³C NMR (CDCl₃, 125 MHz) δ 198.0, 137.0, 133.0, 128.4, 128.2, 26.4; TLC R_(f) 0.32 (EtOAc/Hexane=1/15); HRMS (FI) Calcd for C₈H₈O: 120.0570, found: 120.0569.

¹H NMR (CDCl₃, 400 MHz) δ 7.86-7.85 (m, 2H), 7.26 (d, J=7.6 Hz, 2H), 2.58 (s, 3H), 2.41 (s, 3H); ¹³C NMR (CDCl₃, 125 MHz) δ 197.8, 143.9, 134.7, 129.2, 128.4, 26.5, 21.60; TLC R_(f) 0.25 (EtOAc/Hexane=1/15); HRMS (FI) Calcd for C₉H₁₀O: 134.0726, found: 134.0725.

¹H NMR (CDCl₃, 400 MHz) δ 8.05-8.02 (m, 2H), 7.71-7.68 (m, 2H), 7.65-7.62 (m, 2H), 7.50-7.45 (m, 2H), 7.43-7.38 (m, 2H), 2.65 (s, 3H); ¹³C NMR (CDCl₃, 125 MHz) δ197.7, 145.8, 139.9, 135.9, 128.9, 128.9, 128.2, 127.3, 127.2, 26.6; TLC R_(f)0.3 (EtOAc/Hexane=1/10); HRMS (FI) Calcd for C₁₄H₁₂O: 196.0883, found: 196.0822.

¹H NMR (CDCl₃, 400 MHz) δ 7.91-7.87 (m, 2H), 7.45-7.41 (m, 2H), 2.59 (s, 3H); ¹³C NMR (CDCl₃, 125 MHz) δ 196.7, 139.5, 135.4, 129.6, 128.8, 26.4; TLC R_(f) 0.23 (EtOAc/Hexane=1/20); HRMS (FI) Calcd for C₈H₇ClO: 154.0180, found: 154.0181.

¹H NMR (CDCl₃, 400 MHz) δ 7.84-7.81 (m, 2H), 7.62-7.60 (m, 2H), 2.59 (s, 3H); ¹³C NMR (CDCl₃, 125 MHz) δ 196.9, 135.8, 131.9, 129.8, 128.3, 26.5; TLC R_(f) 0.28 (EtOAc/Hexane=1/15); HRMS (FI) Calcd for C₈H₇BrO: 197.9675, found: 197.9676.

¹H NMR (CDCl₃, 400 MHz) δ 8.33-8.29 (m, 2H), 8.12-8.09 (m, 2H), 2.68 (s, 3H); ¹³C NMR (CDCl₃, 125 MHz) δ 196.2, 150.4, 141.4, 129.3, 123.8, 26.9; TLC R_(f) 0.35 (EtOAc/Hexane=1/5); HRMS (FI) Calcd for C₈H₇NO₃: 165.0420, found: 165.0421.

¹H NMR (CDCl₃, 400 MHz) δ 8.00-7.97 (m, 2H), 7.20-7.16 (m, 2H), 2.58 (s, 3H), 2.31 (s, 3H); ¹³C NMR (CDCl₃, 125 MHz) δ 196.8, 168.8, 154.3, 134.7, 129.9, 121.7, 26.5, 21.1; TLC R_(f)0.30 (EtOAc/Hexane=1/5); HRMS (FI) Calcd for C₁₀H₁₀O₃: 178.0624, found: 178.0625.

¹H NMR (CDCl₃, 400 MHz) δ 7.95-7.92 (m, 2H), 6.95-6.91 (m, 2H), 3.87 (s, 3H), 2.55 (s, 3H); ¹³C NMR (CDCl₃, 125 MHz) δ 196.7, 163.5, 130.6, 130.4, 113.7, 55.4, 26.3; TLC R_(f) 0.35 (EtOAc/Hexane=1/5); HRMS (FI) Calcd for C₉H₁₀O₂: 150.0675, found: 105.0676.

¹H NMR (CDCl₃, 400 MHz) δ 7.77-7.37 (m, 2H), 7.39-7.26 (m, 2H), 2.59 (s, 3H), 2.41 (s, 3H); ¹³C NMR (CDCl₃, 125 MHz) δ 198.3, 138.3, 137.1, 133.8, 128.7, 128.4, 125.5, 26.5, 21.2; TLC R_(f)0.21 (EtOAc/Hexane=1/20); HRMS (FI) Calcd for C₉H₁₀O: 134.0726, found: 134.0724.

¹H NMR (CDCl₃, 400 MHz) δ 7.71-7.68 (m, 1H), 7.40-7.36 (m, 1H), 7.29-7.24 (m, 2H), 2.58 (s, 3H), 2.53 (s, 3H); ¹³C NMR (CDCl₃, 125 MHz) δ 201.7, 138.3, 137.6, 132.0, 131.4, 129.3, 125.6, 29.5, 21.5; TLC R_(f) 0.25 (EtOAc/Hexane=1/20); HRMS (FI) Calcd for C₉H₁₀O: 134.0726, found: 134.0724.

¹H NMR (400 MHz, CDCl₃) δ 8.48 (s, 1H), 8.04 (dd, J=8.6, 1.4 Hz, 1H), 7.97 (d, J=8.0 Hz, 1H), 7.91-7.87 (m, 2H), 7.63-7.54 (m, 2H), 2.74 (s, 3H); ¹³C NMR (125 MHz, CDCl₃) δ 198.1, 135.6, 134.5, 132.5, 130.2, 129.5, 128.4, 128.4, 127.8, 126.7, 123.9, 26.7; TLC R_(f) 0.20 (EtOAc/Hexane=1/20); HRMS (FI) Calcd for C₂H₁₀O: 170.0726; found: 170.0721.

¹H NMR (CDCl₃, 400 MHz) δ 8.80 (dd, J=4.4, 1.6 Hz, 2H), 7.72 (dd, J=4.4, 1.6 Hz, 2H), 2.62 (s, 1H); ¹³C NMR (CDCl₃, 100 MHz) δ 196.6, 150.2, 142.0, 120.5, 25.9; TLC R_(f) 0.20 (EtOAc/Hexane=1/3); HRMS (FI) Calcd for C₇H₇NO: 121.0522, found: 121.0522.

¹H NMR (CDCl₃, 400 MHz) δ8.68 (td, J=4.0, 0.8 Hz, 1H), 8.03 (dd, J=8.0, 0.8 Hz, 1H), 7.82 (dt, J=7.8, 1.6 Hz, 1H), 7.44-7.48 (m, 1H), 2.72 (s, 3H); ¹³C NMR (CDCl₃, 100 MHz) δ 199.4, 153.1, 148.6, 136.4, 136.1, 126.7, 121.1, 25.3; TLC R_(f) 0.25 (EtOAc/Hexane=1/5); HRMS (FI) Calcd for C₇H₇NO: 121.0522, found: 121.0521.

¹H NMR (400 MHz, CDCl₃) δ 7.70 (dd, J=3.5, 1.2 Hz, 2H), 7.64 (dd, J=4.9, 1.2 Hz, 1H), 7.13 (dd, J=4.9, 3.5 Hz, 2H), 2.57 (s, 3H); ¹³C NMR (125 MHz, CDCl₃) δ 190.6, 144.5, 133.7, 132.4, 128.0, 26.8; TLC R_(f) 0.30 (EtOAc/Hexane=1/10); HRMS (FI) Calcd for C₆HOS: 126.0134, found: 126.0133.

¹H NMR (CDCl₃, 400 MHz) δ 2.34-2.30 (m, 1H), 2.11 (s, 3H), 2.19-1.84 (m, 2H), 1.79-1.74 (m, 2H), 1.67-1.63 (m, 1H), 1.33-1.19 (m, 5H); ¹³C NMR (CDCl₃, 100 MHz) δ 212.3, 51.4, 28.4, 27.8, 25.8, 25.6; TLC R_(f) 0.21 (EtOAc/Hexane=1/15); HRMS (FI) Calcd for C₈H₁₄O: 126.1039, found: 126.1036.

¹H NMR (CDCl₃, 400 MHz) δ 8.00-7.98 (m, 2H), 7.64-7.60 (m, 1H), 7.52-7.50 (m, 2H), 4.46 (s, 2H); ¹³C NMR (CDCl₃, 125 MHz) δ 191.3, 134.0, 134.0, 128.9, 128.8, 30.9; TLC R_(f) 0.25 (EtOAc/Hexane=1/20); HRMS (EI) Calcd for C₈H₇BrO: 197.9675, found: 197.9679.

¹H NMR (CDCl₃, 400 MHz) δ 8.03-8.00 (m, 2H), 7.59-7.54 (m, 1H), 7.50-7.45 (m, 2H), 2.71-2.65 (m, 2H), 1.27-1.23 (m, 2H), 1.07-1.02 (m, 2H); ¹³C NMR (CDCl₃, 125 MHz) δ 200.5, 137.9, 132.6, 128.44, 127.9, 17.0, 11.5; TLC R_(f) 0.20 (EtOAc/Hexane=1/15); HRMS (FI) Calcd for C₁₀H₁₀O: 146.0726, found: 146.0727.

¹H NMR (CDCl₃, 400 MHz) δ 7.94 (d, J=7.2 Hz, 2H), 7.55 (tt, J=7.2, 2.0 Hz, 1H), 7.46 (t, J=7.4 Hz, 2H), 3.26 (tt, J=11.2, 3.2 Hz, 1H), 1.91-1.82 (m, 4H), 1.76-1.72 (m, 1H), 1.55-1.25 (m, 5H); ¹³C NMR (CDCl₃, 100 MHz) δ 203.9, 136.4, 132.7, 128.6, 128.3, 45.6, 29.4, 26.0, 25.9; TLC R_(f) 0.3 (EtOAc/Hexane=1/10); HRMS (FI) Calcd for C₁₃H₁₆OF₃: 188.1196, found: 188.1195.

¹H NMR (CDCl₃, 400 MHz) δ 7.70-7.67 (m, 2H), 7.47-7.37 (m, 3H), 1.35 (s, 9H); ¹³C NMR (CDCl₃, 125 MHz) δ 209.3, 138.6, 130.7, 128.0, 127.8, 44.2, 28.0; TLC R_(f) 0.4 (EtOAc/Hexane=1/20); HRMS (FI) Calcd for C₁₁H₁₄O: 162.1039, found: 162.1038.

¹H NMR (CDCl₃, 400 MHz) δ 7.82-7.80 (m, 4H), 7.62-7.57 (m, 2H), 7.51-7.47 (m, 4H); ¹³C NMR (CDCl₃, 125 MHz) δ 196.7, 137.5, 132.4, 123.0, 128.2; TLC R_(f)0.35 (EtOAc/Hexane=1/10); HRMS (FI) Calcd for C₁₃H₁₀O: 182.0726, found: 182.0725.

¹H NMR (CDCl₃, 400 MHz) δ 7.76 (d, J=7.2 Hz, 1H), 7.61-7.57 (m, 1H), 7.50-7.47 (m, 1H), 7.39-7.35 (m, 1H), 3.15 (t, J=6.0 Hz, 2H), 2.71-2.68 (m, 2H); ¹³C NMR (CDCl₃, 125 MHz) δ 206.9, 155.1, 137.0, 134.5, 127.2, 126.6, 123.6, 36.1, 25.7; TLC R_(f)0.3 (EtOAc/Hexane=1/10); HRMS (FI) Calcd for C₉H₈O: 132.0570, found: 132.0570.

CF₃CH₂OH (Trifluoroethanol): ¹H NMR (400 MHz, CDCl₃) δ 3.92 (q, J=8.8 Hz, 2H), 3.21 (br, 1H, OH); ¹⁹F NMR (470 MHz, CDCl₃) δ −79.08 (s).

CF₃CHO (Trifluoroacetaldehyde; b.p. −18° C.): ¹⁹F NMR (470 MHz, CDCl₃) δ −84.62 (s)

¹H NMR (CDCl₃, 500 MHz) δ 3.98 (sept, J=6.5 Hz, 1H), 3.17 (s, 1H, OH), 1.38 (d, J=6.5 Hz, 3H); ¹⁹F NMR (470 MHz, CDCl₃) δ −81.4 (s).

¹H NMR (CDCl₃, 500 MHz) δ 2.48 (s, 3H); ¹⁹F NMR (470 MHz, CDCl₃) δ −80.0 (s).

Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. 

What is claimed is:
 1. A method for oxidative cleavage of a compound with an unsaturated double bond, comprising the steps of: (A) providing a compound (I) with an unsaturated double bond, a trifluoromethyl-containing reagent, and a catalyst;

wherein, R₁ and R₂ are each independently H, C₁₋₂₀ alkyl, C₃₋₂₀ cycloalkyl, C₆₋₁₈ aryl, or C₄₋₁₈ heteroaryl, or R₁ and R₂ are fused to be C₆₋₁₈ aralkyl; R₃ is H, C₁₋₁₀ alkyl, C₃₋₁₀ cycloalkyl, C₆₋₁₀ aryl, or C₄₋₁₀ heteroaryl, with the proviso that R₁, R₂ and R₃ are not H at the same time; wherein the catalyst is represented by Formula (II): M(O)_(m)L¹ _(y)L² _(z)  (II) wherein, M is a metal selected from the group consisting of IVB, VB, VIB, and actinides; L¹ and L² are each a ligand; m and y are integers greater than or equal to 1; and z is an integer greater than or equal to 0; (B) mixing the compound with the unsaturated double bond and the trifluoromethyl-containing reagent to perform an oxidative cleavage of the compound with the unsaturated double bond by using the catalyst in air or under oxygen atmosphere condition to obtain a compound represented by Formula (III):


2. The method of claim 1, wherein R₁ and R₂ are each independently H, C₁₋₁₀ alkyl, C₃₋₁₀ cycloalkyl, C₆₋₁₄ aryl, or C₄₋₁₀ heteroaryl, or R₁ and R₂ are fused to be C₆₋₁₂ aralkyl; R₃ is H, C₁₋₆ alkyl, C₃₋₆ cycloalkyl, C₆₋₁₀ aryl, or C₄₋₁₀ heteroaryl.
 3. The method of claim 1, wherein L¹ is selected from the group consisting of OTf, OTs, NTf₂, halogen, RC(O)CH₂C(O)R, OAc, OC(O)R, OC(O)CF₃, OMe, OEt, O-iPr, and butyl, wherein R is alkyl.
 4. The method of claim 1, wherein L² is selected from the group consisting of Cl, H₂O, CH₃OH, EtOH, THF, CH₃CN,

and ligand containing C═N unit.
 5. The method of claim 4, wherein the ligand containing C═N unit comprises pyridine, oxazole, oxazoline, or imidazole.
 6. The method of claim 5, wherein the ligand containing C═N unit is represented by Formula (V):

wherein R₆ and R₇ are each independently H, C₁₋₅ alkyl or C₃₋₆ cycloalkyl.
 7. The method of claim 4, wherein the ligand containing C═N unit is represented by Formula (IV):

wherein, R₄ and R₅ are each independently halogen, nitro, C₁₋₁₀ alkyl, C₆₋₁₈ aryl, or C₄₋₁₈ heteroaryl.
 8. The method of claim 1, wherein the catalyst represented by Formula (II) is MoO₂Cl₂, V(O)Cl₃, V(O)(O-iPr)₃, V(O)Cl₂, V(O)(OAc)₂, V(O)(O₂CCF₃)₂, Ti(O)(acac)₂, Zr(O)Cl₂, Hf(O)Cl₂, Nb(O)Cl₂, MoO₂(acac)₂, V(O)(OTs)₂, VO(OTf)₂, or V(O)(NTf₂)₂.
 9. The method of claim 1, wherein the catalyst represented by Formula (II) is any one of formulas (II-1) to (II-4):


10. The method of claim 1, wherein the trifluoromethyl-containing reagent is 3,3-Dimethyl-1-(trifluoromethyl)-1,2-benziodoxole, 3,3-Dimethyl-1-(perfluroalkyl)-1,2-benziodoxole, 3-oxo-1-(trifluoromethyl)-1,2-benziodoxole, 3-oxo-1-(perfluroalkyl)-1,2-benziodoxole), trifluomethyl dibenzothiophenium salts, perfluoroalkyl dibenzothiophenium salts, CF₃SO₂Na, or CF₃(CF₂)_(n)SO₂Na, wherein n is an integer of 1 to
 6. 11. The method of claim 1, wherein step (B) further obtains a trifluoroketone- or trifluoroaldehyde-containing compound represented by the following formula (VI), trifluoroalkyl alcohol represented by the following formula (VII) or a combination thereof:

wherein R₃ is H, C₁₋₁₀ alkyl, C₃₋₁₀ cycloalkyl, C₆₋₁₀ aryl, or C₄₋₁₀ heteroaryl; n is an integer of 0 or 1 to
 6. 